This invention relates to hardcopy devices, and more particularly to an input converger for accurate control of media movement therethrough.
Hard copy devices process images on media, typically taking the form of scanners, printers, plotters (employing inkjet or electron photography imaging technology), facsimile machines, laminating devices, and various combinations thereof, to name a few. These hardcopy devices typically transport media in a sheet form from a supply of cut sheets or a roll, to an interaction zone where scanning, printing, or post-print processing, such as laminating, overcoating or folding occurs. Often different types of media are supplied from different supply sources, such as those containing plain paper, letterhead, transparencies, pre-printed media, etc.
The relative position of the paper and the operative structures in the interaction zone is precisely maintained to effect high-quality media processing in the interaction zone. For example, in the case of an inkjet printer, printing occurs in the interaction zone and the position of an ink cartridge as it reciprocates in a back and forth motion across the media, and the positioning and control of paper as it advances past the printheads in the ink cartridge are controlled to produce high quality images. The media advancement through the hardcopy devices, and the positioning of the operators in the interaction zone are typically separately controlled, although their operation is coordinated with a hardcopy controller.
Hardcopy apparatus typically include media advancement mechanisms that serve to advance the recording media from one or more media sources through a media feed path and through the interaction zone. Again in the case of an inkjet printer, the interaction zone is typically a xe2x80x9cprintzonexe2x80x9d where ink is applied to the paper. The media advance mechanisms move the paper through the interaction zone the desired distance, often in incremental steps, at the desired rate, and in a manner such that the media is oriented correctly relative to the devices found in the interaction zone. Achieving high quality media processing is often impeded by media feed errors such as overfeeding and underfeeding, and misalignment errors such as skewing.
The illustrated embodiment relates to apparatus for advancing media through a hardcopy device. A cylindrical guide wheel having a first radius is mounted on a shaft having an axis transverse to a media feed path axis. A guide surface is spaced apart from the guide wheel to define a media feed path therebetween. A drive wheel having an extended portion that is concentric with the guide wheel, and which has a greater radius than the first radius is fixed to the shaft. A pinch roller communicates with the media feed path.